Press



June 21 19727.

J. S. GULLBORG PRES S Filed Aug. 31. 1923 '1 shuts-sheet 1 June 21 1927'J. 5., GULLBORG PRESS Filed Aug. 31. 1923 7 Shoots-Sheet 2 fizz/622%Tofin 5. Galffiorg d/ifiess y 7 Shoots-Sheet 3 Jiwenf J. 5. GULLBGRGPRESS Filed Aug. 31. 192:5

June 21 1927.

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PRESS Filed Aug. 31. 1923 '7 Shoots-Sheet 6 June 21 1927. a GULLBGG 9PRESS Filed Aug. 31. 1923 '7 Shoots-Sheet 7 JFUGZZW Patented June 21,1927.

UNITED STATES PATENT OFFICE.

JOHNS. GULLBORiG, 01 CHICAGO, ILLINOIS, ASSIGNOR, IBY MESNE ASSIGNMENTS,TO

ALEMI'IE DIE-CASTING & MIG. 00., OF CHICAGO, ILLINOIS, A CORIBORATIO NOF ILLDIOIS.

PRESS.

. Application filed Aug-nit 31, 1988. Serial No. 680,308.

My invention relates to presses. While the invention is primaril relatedto resses, it will be understood rom the fo lowlng specification andclaimsthat it is not intended to limit the invention to use in pressesonly as the rinciples thereof may be applied in mac ines of a similarclass where a large force is to be developed.

While the particular embodiment which I shall herein illustrate anddescribe is a hydraulic press, it is to'be understood that i able sourceof power, and convert the motion of the .same into a reciprocatingmotion 'of relatively slow action and short travel in a predeterminedfixed'path, but with great mechanical advantage or leverage, so as toexert eat force or pressure. This motion alone is not suitable forcompressing a body to any great extent unless the same is to extendthrough only a very short range. This is because the traverse of thereciprocating member is limited and is, in practice, preferably only afraction of an inch. Hence, when the work to be done requires a't-ravelof the head or jaws or other object engaging members through aconsiderable distance, such limited reciprocatory motion, while it iscapable of exerting suflicient pressure, is not capable unaided ofcovering the required path. I provide additional means in the shape ofan extensible connection between one of the jaws or other workengagingmembers for following up the work and taking up the lost motion upon thereturn or in-Mroke of the reciprocating plunger. In other words, Iextend the application of the force to a point in advance of its firstapplication. Where the load is not a constant load, this interposition;of the extensible connection maybe done quite easily manually byinserting a wedge or turncompressed, there is a tendency for the load to.set or remain and the pressure between the load and th p ng r 1 98 f rth It like may readily be a turn stroke than it was upon the out stroke.In such case, the wedge or jackscrew or the vanced upon the cessation ofpressurebetween the parts. However, when the load is a uniform one orsubstantially uniform, as, for example, when the load is a gravity loadto be raised, additional means must be provided for holding the load inits advanced position to permit the introduction of the extensibleconnection. Whereas the plunger reciprocates or traverses a closed path,the extensible connection does not do so, but,present s. an irreversiblepower transmitt-in tle force as compared with the reciprocating member.

' The ress of the present invention is par device of rel- T atlvelygreat strength, but 0 relatively litticular y useful in connection withthe I formlng of metal under pressure. This is which permits of a si le,form of press. but furthermore, the u mits of a novel mode- ,oftreatment of the metal or similar material. The transmitting connectionwhich imparts the reciprocatory motion to the plunger gives itasine-wave due to the unsymmetriclgnature of the load of the press per gmotion, that is, a motion like the motion of I 1 a crank driven pistonin a cylinder, starting slowly, speeding up in the middle of the stroke,and again stopping slowly, all without impact or shock which has ashattering effect. This sine-wave form of motlon gives the metal orother material time i to start it slow, then moves it rapidly, and againgives it time to set. The force of the stroke throughout this movementis in inverse proportion to its speed, and this is highly beneficial inthat maximum force is provided for overcoming the static friction of theparticles and again maximum force is available as the-particles come torest.

The range of motion may be selected to the heat to be dissipated andpermitting the grain of the metal to assume its new position without soeat injury or 'so greatva resistance as mig t be caused by a continuousmotion.

a ord r to q n was ems in as art with the manner of constructing and op-.erating the device of my invention and practicing the method thereinembodied, I shall now describe a particular press and its mode ofoperation. 1

In the accompanying drawings Fig. 1 is a side elevational view of apress embodying my invention;

Fig. 2 is a plan view of the hydraulic pulsator or vibrator;

Fig. 3 is a side elevational view of the same;

Fig. 4 is an end view taken from the right of Fig. 3;

Fig. 5 is a plan view of the press;

Fig. 6 is a longitudinal vertical section taken on the line 6-6 of Fig.8;

Fig. 7 is a longitudinal .vertical section taken on the line 7-7 ofFig.5;

Fig. 8 is a horizontal section taken on the line 8-8 of Fig. 1;

' Fig. 9 is a fragmentary sectional vlew of the take-up wedge viewed onthe line 9-9 of Fig. 8; and

Fig. 10 is a similar sectional view through v the guides, as indicatedon the line 10-10 of Fig. 11 is a fragmentary view of a die blank;

Fig. 12 shows the. type of hob used in forming the die.

The device shown in Fig. 1 comprises a mechanically driven hydraulicpulsator 1 and a hydraulically operated press 2 connected together by ahydraulic connection or pipe 3. The hydraulic connection between thepulsator 1 and the press 2 constitutes a closed system without anyautomatic valves. This hydraulic system-1s closed by a high presurehydraulic valve 4 of great strength to resist the enormous fluidpressures which are created in the closed system. The vibrator 1comprises essentially a cylinder 5 and a cooperating reeiprocable piston6, shown more clearly in. Figs. 2, 3 and 4.

The cylinder 5 comprises a relatively unlinished interior wall in whichthe liquid is confined by a stufling box or gland 7 which his closelyabout the plunger 6. The plunger 6 is of relatively small diameter andhas a fairly long stroke, that is to say. of the order of twice thebore. although these proportions maybe varied, as will be appreciated bythose skilled in the art. The cylinder 5 is securely mounted upon a baseor frame member 8.

- This base 8 provides a suitable split box or hearing 9, said bearingbeing split in such a manner as to relieve the cap of the hearing frommajor stresses, as is common in engine practice. A heavy crank shaft hassuitable bearings in the boxes 9 and this crank shaft has a crank 11.the crank pin of which is connected through a suitable connecting rod 12to a cross head 18 mounted in guides 14 on the bed or frame member 8.This cross head is suitably connected to the plunger 6. At the outsideof the top bearing 9, asv viewed in Fig. 2, I provide a worm gear andwheel housing 15 which Is provided with an outboard hearing In for theend of the crank shaft it). Within this housing 15 and securely keyed tothe crank shaft 10 is a worm wheel 17, and cooperating with it is a worm'18. This worm 18 is mounted on a suitable drive shalt 19, said shafthaving hearings, in this case antifriction bearings 20 and 21, at theend of the housing 15. The housing 15 forms a container for a suitablelubricant. The outer races for the anti-friction bearings 20 and 2t areseated in stationary annular seats in the ends of the'housing 15 and thesame are held in said annular seats by rings 22 and 23 which overhangsaid outer races. The inner races are' held in place upon the shaft 19by suitable collars 24 and 25 secured upon said shaft; 19. Thesebearings 20 and 21 are preferably ball bearings, adapted to take notonly the radial thrust, but also the end thrust caused by the mutualaction of the worm and worm wheel. A suitable driving pulley 26 is keyedu on the end of thejworm shaft 19 and this w eel serves not only as adriving belt pulley, but alsoas a fly wheel to assist in the overcomingof momentary high resistance to the action of the )lunger 6. The wheel26 is adapted to be driven by a belt trained over it and trained overthe pulley of a suitable electric motor. The inertia of the flywheel 26is intended to be and is made great enough to throw the crank 11 overcenter when it encounters a particularly high resistance near the end ofits stroke. Thus, as will be explained more in detail later, there isavailable not only the maximum pressure due to the sinenvave characterof the stroke of the piston (l, but also the inertia of the .tly wheelback of it. This will be better understood when the crank and theconnecting rod are considered as-parts of a toggle for exerting a highpressure upon the piston 6 as it nears the end of its outward stroke.

The in and out reciprocatory motion of the piston 6 in its cylinder 5 istransmitted to the cylinder of the press 2.

The press 2 com )rises a space member 28 providing a cylizu er 29inwhich there is guided the hydraulic piston 30. This piston 30 closelyfits the bore of the upper end of the cylinder 29. A suitable flexiblepacking ring 31 is held in place by a retainer ring 32 to pack the jointagainst leakage. The piston 30 ismade hollow for the purpose ofdecreasing the weight of the same. andsuitable strengthening webs areformed on the interior thereof to brace it against the stresses to whichit is subjected. Since the piston is hollowand there would be a tendencyto trap air in the'same, I provide a suitable bleeding opening or ventin the iii) as indicated at 35 for cooperating with the takeup wedge 36.It has, furthermore, a-

suitable lug 37 for mounting the lead screw 38 for the Wedge 36. The lug37 is preferably provided with a suitable bushing having threadscooperating with the lead screw 38. The lead screw is preferablyprovided with a hand wheel 39 for turning said screw,

although any other suitable means for turning said lead screw may beemployed.

The frame member 28 is provided with a suitable pedestal 40 forsupporting the entire press and for mounting the same upon a suitablefoundation. This frame member 28 has four equally spaced lugs around itssides, the lugs being indicated at 41 in Fig. 7, and in these lugs aremounted the guide and tie-rods 42. The rods-42 are shouldered, asindicated at 43, and suitable collars 44 are set between these shouldersand the top edges of the lugs 41. rods are threaded and threaded collarsor nuts 44 hold these rods in place. At the upper ends of the rods Ihave provided a platen or bed 45, which similarly has .four lugs 46mounted upon the upper ends of the rods in a simpler manner.

The intermediate parts of the rods 42 are finished to form guides forthe collars 47 which extend outwardly from and form parts of the platen34. These collars 47 may be providedwith suitable bushings, if desired,for renewing the bearing surfaces. A pair of guide pins 4849 are mountedin the guiding frame 47, and a suitable head 50, which has lugs 51 and52, is guided on said pins. The Wedge 36 lies between the head 50'andthe guide frame 47, being rabbeted into the guide frame 47 and the head50 being rabbeted into the wedge 36, as will be applarent from Figs. 7and 9. The wedge 36 as a pair of depending lugs 54, as shown in Fig. 6,which are adapted to fit over the reduced portion55 of the end of thelead screw 38, to connect said lead screw and wedge together. The lugs54 are adapted to travel in a recess 56, formed in the top surface ofthe guide frame 34. It will be observed that the feed screw 38 isstationary in its lug 37 and that the depending lugs 54 travel upward asthe wedge is advanced. A suitable wear plate 57 is secured at the frontend of the wedge 36 in advance of the lugs 54' to take the pressure ofthe feed screw 38 as the wedge forced between the guide frame 34 and thehead 50.

The i t rior of the cylinder 29 is con- The lower ends of the.

nected to the pulsator through the pipe 3. The high pressure shut-offvalve 4 (see Figs. 6 and 8) is in practice placed adjacent the side ofthe press where it is convenient for the operator. I have shown thevalves further removed in Fig. 1 in order to make a g clear diagram ofthe connection. The high sewer; and the connection 63 leading to thehigh pressure valve 4. The system is charged with water by opening thehigh pressure valve 4 and the vent plug 33 in the plunger 30 of thepress 2. The stop and waste cook 59 is then moved to the on position,connecting the pipe 3 to the city water main 61 for filling of thesystem with water.

The plunger 30 of the press 2 is of such an' area that the pressure ofthe city water readily raises the same to the desired height. 'After allof the air has been\expelled from the system, the plug 33 is closed.There upon, the cock 59 may be closed and the high pressure valve 4 isclosed. The drive wheel 26 is turned by the driving motor and this inturn operates the plunger 6 of the pulsator 1 at agreatly reduced speed,but with greatly increased force. This plunger or piston 6 has a motionof aicharacter well known by those skilled in the art, the speed ofwhich varies in accordance with the sine of the angle of the crank whichdrives it. We may term this harmonic motion. The plunger 30- of thepress and its connected parts partakes of the same character of motion,that is to say, it has a harmonic motion of greatly reduced travel, butalso greatlyincreased force. Thus assume that the system has been filledwith suitable liquid, preferably water, and that the plunger 30 has beenset at the proper height, any object to be compressed may be placed uponthe block. 50. The plunger 30 will then be raised and lowered as theplunger 6 is moved in and out of the cylinder 5. Since there are novalves, such as check valves, to be taken into account, the liquid inthe closed system may be subjected to very high pressures. and as aresult enormous force may be exerted upon the object between the block50 and the platen 45. As the piston 30 rises and falls, the pressureupon the object will be increased and decreased accordingly. In order tofollow up the first compression stroke of the plunger 30. the operatorturns the hand wheel 39 to advance the screw 38 and thus enter the wedge36 to a greater extent between the block 50 and the frame 34. The'wedge,while it is of very small lead or angle, and is therefore self'locking,is of itself a means for raising the head 50, but of vastly less forcethan the plunger 30. Hence the o ierator will normally be unable toadvance die feed screw 38 while thepiston is moving upwardly, but assoon as it starts on. its downward excursion he will be able to turn thewheel 39 and thus advance the wedge between the frame 34 and the head 50to take up the advance which had been made by the revious u stroke ofthe plunger 30. It wil at once that the wedge and lead screw are but oneof many ways in which this advance may be taken up and that a suitablejack screw or the like might be employed instead of the equivalent ofwhat I have shown. However, I find that less space is required by thewedge as I have employed it than would be required for a ljackscrew.Moreover, the construction whic 1 I employ is simple and relativelyinexpensive and'easy to machine.

It is also to be understood that I do not limit the-invention to theemployment of a hydraulic connection for increasin the mechanicaladvantage or levera e, an that for certain classes of work succonnection is not necessary.

The invention is of value regardless of th manner employed inreciprocating the, actuating'plunger 30.

A particularly useful application of the principles of my invention isfound in the bobbing of dies. Thus, for instance, let it be assumed thatit is desired to make a number of moulds all of like form to be used atthe same time for forming articles. In die-casting and the like work, anumber of identical dies for the same object are often highly desirable.The same thin is true in moulded work for such materi'a as bakelite,condensite, etc. It is customary to form the dies of steel. The practiceknown as die-bobbing has come into general use. This consists in forminga positive or male die member corresponding to the shape of the articleitself and forcing said hob into a suitable piece of steel to form themould. Heretofore, it has been customary to force the hob into the steel-blank under hydraulic pressure. 7

I find that my press is peculiarly useful in work of this character andin fact in any work in which high pressures are employed to produce aflow of the material under consideration.

In Fig. 11 I have shown a piece of stock area for applying pressure.

e understood In employing the device of my invention the blan 65 is laidupon the head 50 with a suitable pad or pillow block between them, andthen t is hob 68 is set in place upon said blank. A suitable pillowblock may be interposed between the top of the hob 67 and the platen 45,if desired. Whereu on, the pulsator 1 is set into operation. 4 is openedand the cock 59 is opened to admit city water pressure to brin the jawsof the press into engagement wit the hob and blank. Thereu on, thevalves 59 and {l are closed ofi. tig t. The plunger, with itscooperating parts now reciprocates up and down with a harmonic motion ofrela- T. e valve tively short extent. The pressure is great until thehob is embedded in theblank to thedesired degree. I This action ofrepeated impulses of pressure separated by a period of cessation ofpressure is highly desirable. It permits the metal to start its flow andcarry it through a certain cycle, and then rest for a moment and againtake up its travel. The wear upon the hob is greatly reduced and thework is made much easier. The heating of the particles by flow over eachother has a.

chance to be dissiated between periods of movement, and it is possiblefor a lubricant to find its way into the working space between periodsof pressure. 1

This action of intermittent flow and cessation of flow is highlyadvantageous in other cases where metal or other material is to beshaped or caused to flow, orthe'particles to move with res ect toeach-other.

I do not intend to limited to the details shown or described, or to the,materials which I have referred to in the above specific embodiment ofthe invention.

I claim v 1. In a hydraulic press system, a hydraulic press including acylinder, a piston reciprocably mounted in the cylinder, and a platenspaced from and connected to the cylinder having a portion cooperablewith the top of the piston, a pulsator including a reciprocatory memberhaving a small amplitude of movement, but moving with great force. saidmember moving slowly initially, speeding up in the middle of the stroke,and ending the stroke relatively slowly, and

a fluid connection between the press cylinder and said reciprocatorymember for causing the force of said member to be applied to andmagnified by the liquid in the press to actuate said press piston, saidmovement of the reciprocatory member causing said press piston to movethe metal being worked slowly initially to move it more rapidly on theintermediate portion of the stroke and to move it slowly finally so asto give the metal time to set.

2. In a hydraulic press system, ahydraulic press including a cylinderand a reciprocable piston therein having a metallic object to be workedthereon, said piston being adapted to be set initially in a givenposition, a pulsator including a reciprocatory member having a crankmovement, a fluid connection between the liquid in the cylinder and saidreciprocatory member for causing the force of said member to be appliedto and magnified by the liquid in the cylinder to actuate said presspiston, and take-up means associated with the press operable during theretrograde movement of the pulsator member to advance the metallicobject and load on the piston, said crank movement ofthe reciprocatorymember causing said press piston to move the metal being worked slowlyinitially, to move it more rapidly on the intermediate portion of thestroke and to move it slowly finally so as to give the metal time toset.

In Witness whereof, I hereunto subscribe my name this 28th day ofAugust, 1923.

J OHlN S. GULLBORG.

